This has been a subject on many film forums, I have been using a wax/silicone mixture for quite some time now, and I find it to be very good, some films that ran unstable now run very smoothly, even a well known film projector repairer has tried it, after asking me what it was. I had a film with VS that I have been treating once a month or so, last time I opened the case I could not smell it, maybe wishful thinking, I'm due to treat it again soon so I'll report back. The price of this is £3.99 for 500ml and it can be purchased on the high-street. I had a very dirty scratched standard 8 print from E-bay, a few passes with this cleaner, not only did it remove the dirt, and it was a lot, but I was amazed at the amount of scratches that disappeared when I projected it, it looked like a different film.